Factory overclocked GTX 980 Ti's with custom cooling will always be faster than a TitanX. The reference cooler and reference components common to all TitanX's ensures that their Turbo Boost clocks will be modest in comparison. Pick a custom MSI GTX 980 Ti Gaming with the Twin Frozr cooler, or one of the very nice models with all-in-one liquid cooling, and the TitanX just becomes an expensive and lower performing marketing gimmick for people where "budget is not a problem".